The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.

Although sketch-to-photo retrieval has a wide range of applications, it is costly to obtain paired and rich-labeled ground truth. Differently, photo retrieval data is easier to acquire. Therefore, previous works pre-train their models on rich-labeled photo retrieval data (i.e., source domain) and then fine-tune them on the limited-labeled sketch-to-photo retrieval data (i.e., target domain). However, without co-training source and target data, source domain knowledge might be forgotten during the fine-tuning process, while simply co-training them may cause negative transfer due to domain gaps. Moreover, identity label spaces of source data and target data are generally disjoint and therefore conventional category-level Domain Adaptation (DA) is not directly applicable. To address these issues, we propose an Instance-level Heterogeneous Domain Adaptation (IHDA) framework. We apply the fine-tuning strategy for identity label learning, aiming to transfer the instance-level knowledge in an inductive transfer manner. Meanwhile, labeled attributes from the source data are selected to form a shared label space for source and target domains. Guided by shared attributes, DA is utilized to bridge cross-dataset domain gaps and heterogeneous domain gaps, which transfers instance-level knowledge in a transductive transfer manner. Experiments show that our method has set a new state of the art on three sketch-to-photo image retrieval benchmarks without extra annotations, which opens the door to train more effective models on limited-labeled heterogeneous image retrieval tasks. Related codes are available at https://github.com/fandulu/IHDA.

Pretrained language models have demonstrated extraordinary capabilities in language generation. However, real-world tasks often require controlling the distribution of generated text in order to mitigate bias, promote fairness, and achieve personalization. Existing techniques for controlling the distribution of generated text only work with quantified distributions, which require pre-defined categories, proportions of the distribution, or an existing corpus following the desired distributions. However, many important distributions, such as personal preferences, are unquantified. In this work, we tackle the problem of generating text following arbitrary distributions (quantified and unquantified) by proposing Nano, a few-shot human-in-the-loop training algorithm that continuously learns from human feedback. Nano achieves state-of-the-art results on single topic/attribute as well as quantified distribution control compared to previous works. We also show that Nano is able to learn unquantified distributions, achieves personalization, and captures differences between different individuals' personal preferences with high sample efficiency.

Image super-resolution is a common task on mobile and IoT devices, where one often needs to upscale and enhance low-resolution images and video frames. While numerous solutions have been proposed for this problem in the past, they are usually not compatible with low-power mobile NPUs having many computational and memory constraints. In this Mobile AI challenge, we address this problem and propose the participants to design an efficient quantized image super-resolution solution that can demonstrate a real-time performance on mobile NPUs. The participants were provided with the DIV2K dataset and trained INT8 models to do a high-quality 3X image upscaling. The runtime of all models was evaluated on the Synaptics VS680 Smart Home board with a dedicated edge NPU capable of accelerating quantized neural networks. All proposed solutions are fully compatible with the above NPU, demonstrating an up to 60 FPS rate when reconstructing Full HD resolution images. A detailed description of all models developed in the challenge is provided in this paper.

The role of mobile cameras increased dramatically over the past few years, leading to more and more research in automatic image quality enhancement and RAW photo processing. In this Mobile AI challenge, the target was to develop an efficient end-to-end AI-based image signal processing (ISP) pipeline replacing the standard mobile ISPs that can run on modern smartphone GPUs using TensorFlow Lite. The participants were provided with a large-scale Fujifilm UltraISP dataset consisting of thousands of paired photos captured with a normal mobile camera sensor and a professional 102MP medium-format FujiFilm GFX100 camera. The runtime of the resulting models was evaluated on the Snapdragon's 8 Gen 1 GPU that provides excellent acceleration results for the majority of common deep learning ops. The proposed solutions are compatible with all recent mobile GPUs, being able to process Full HD photos in less than 20-50 milliseconds while achieving high fidelity results. A detailed description of all models developed in this challenge is provided in this paper.

近年来，在自学学习（SSL）方面取得了重大成功，这有助于各种下游任务。但是，攻击者可能会窃取此类SSL模型并将其商业化以获利，这对于保护其知识产权（IP）至关重要。大多数现有的IP保护解决方案都是为监督学习模型而设计的，不能直接使用，因为它们要求模型的下游任务和目标标签在水印嵌入过程中已知并获得，这在SSL的域中并非总是可以的。为了解决此类问题，尤其是在水印嵌入过程中下游任务多样化且未知时，我们提出了一种新型的黑盒水印解决方案，名为SSL-WM，以保护SSL模型的所有权。 SSL-WM将水印编码器的水印输入映射到不变的表示空间中，该空间会导致任何下游分类器产生预期的行为，从而允许检测到嵌入式水印。我们使用不同的SSL模型（包括基于对比度和基于生成的生成型）来评估许多任务，例如计算机视觉（CV）和自然语言处理（NLP）等许多任务。实验结果表明，SSL-WM可以有效地验证各种下游任务中被盗SSL模型的所有权。此外，SSL-WM对模型进行微调和修剪攻击非常强大。最后，SSL-WM还可以从评估的水印检测方法中逃避检测，从而证明了其在保护SSL模型IP时的有希望的应用。

基于AI的蛋白质结构预测管道（例如AlphaFold2）已达到了几乎实验的准确性。这些高级管道主要依赖于多个序列比对（MSA）和模板作为输入来从同源序列中学习共进化信息。但是，从蛋白质数据库中搜索MSA和模板很耗时，通常需要数十分钟。因此，我们尝试通过仅使用蛋白质的主要序列来探索快速蛋白质结构预测的极限。提出了Helixfold单一的形式将大规模蛋白质语言模型与AlphaFold2的优质几何学习能力相结合。我们提出的方法，Helixfold单个，首先预先培训是一种大规模蛋白质语言模型（PLM），使用了数以千计的主要序列利用自我监督的学习范式，将用作MSA和模板的替代方法共同进化信息。然后，通过将预训练的PLM和AlphaFold2的必需组件组合在一起，我们获得了一个端到端可区分模型，以仅从主要序列预测原子的3D坐标。 Helixfold-Single在数据集CASP14和Cameo中得到了验证，通过基于MSA的方法，具有大型同源家庭的基于MSA的方法，从而实现了竞争精度。此外，与主流管道进行蛋白质结构预测相比，Helixfold单个的时间比主流管道的时间少得多，这表明其在需要许多预测的任务中的潜力。 HelixFold-Single的守则可在https://github.com/paddlepaddle/paddlehelix/tree/dev/dev/pprotein_folding/helixfold-single上获得，我们还在https://paddlehelix.baidu.com上提供稳定的Web服务。 /app/drug/protein-single/prevast。

准确的蛋白质结构预测可以显着加速生命科学的发展。 Alphafold2的准确性是边界端到端结构预测系统，已经接近实验确定技术的准确性。由于复杂的模型体系结构和大量的内存消耗，因此需要大量的计算资源和时间来实施从头开始实施Alphafold2的训练和推断。对于大多数个人和机构来说，运行原始AlphaFold2的成本都是昂贵的。因此，降低这一成本可以加速生命科学的发展。我们使用PaddlePaddle（即HelixFold）实现Alphafold2，以提高训练和推理速度并减少记忆消耗。操作员融合，张量融合和混合并行性计算改善了性能，而通过重新计算，BFLOAT16和内存读/写入/编写就场，内存进行了优化。与原始的Alphafold2（由JAX实施）和OpenFold（由Pytorch实施）相比，HelixFold仅需7.5天即可完成完整的端到端培训，并且在使用Hybrid ParalleleSism时只需要5.3天，而Alphafold2和OpenFold都可以使用11个。天。 Helixfold节省了1倍的训练时间。我们验证了HelixFold的准确性可能与CASP14和CAMAO数据集上的Alphafold2相当。 HelixFold的代码可免费下载：https：//github.com/paddlepaddle/paddlehelix/paddlehelix/tree/dev/dev/pprotein_folding/helixfold，我们还在https://paddlehelix.baidu.com/com上提供稳定的Web服务。应用程序/药物/蛋白质/预测。

作为智能机器人的一项基本任务，Visual Slam在过去几十年中取得了长足的进步。但是，在高度弱质地的环境下，强大的大满贯仍然非常具有挑战性。在本文中，我们提出了一个名为RWT-Slam的新型视觉大满贯系统，以解决这个问题。我们修改LOFTR网络，该网络能够在低纹理的场景下产生密集的点匹配以生成特征描述符。为了将新功能集成到流行的Orb-Slam框架中，我们开发了功能面具，以滤除不可靠的功能并采用KNN策略来增强匹配的鲁棒性。我们还对新的描述符进行了视觉词汇，以有效地循环结束。在TUM和Openloris等各种公共数据集以及我们自己的数据中测试了由此产生的RWT-SLAM。结果显示在高度弱质地的环境下表现非常有希望。

视频修复旨在从多个低质量框架中恢复多个高质量的帧。现有的视频修复方法通常属于两种极端情况，即它们并行恢复所有帧，或者以复发方式恢复视频框架，这将导致不同的优点和缺点。通常，前者具有时间信息融合的优势。但是，它遭受了较大的模型尺寸和密集的内存消耗；后者的模型大小相对较小，因为它在跨帧中共享参数。但是，它缺乏远程依赖建模能力和并行性。在本文中，我们试图通过提出经常性视频恢复变压器（即RVRT）来整合两种情况的优势。 RVRT在全球经常性的框架内并行处理本地相邻框架，该框架可以在模型大小，有效性和效率之间实现良好的权衡。具体而言，RVRT将视频分为多个剪辑，并使用先前推断的剪辑功能来估计后续剪辑功能。在每个剪辑中，通过隐式特征聚合共同更新不同的帧功能。在不同的剪辑中，引导的变形注意力是为剪辑对齐对齐的，该剪辑对齐可预测整个推断的夹子中的多个相关位置，并通过注意机制汇总其特征。关于视频超分辨率，DeBlurring和DeNoising的广泛实验表明，所提出的RVRT在具有平衡模型大小，测试内存和运行时的基准数据集上实现了最先进的性能。